[Antitumor activity of bacterial fractions and related synthetic compounds]

We have purified the cell-wall skeletons (CWS) of Mycobacterium bovis BCG, Nocardia rubra, Propionibacterium acnes and Listeria monocytogenes as the adjuvant-active principles of these bacterial cells. These cell-wall skeleton preparations were shown to have antitumor activities in experimental tumor systems. Especially BCG-CWS and N. rubra-CWS were applied for the treatment of human cancer. The synthetic immunoadjuvants such as cord factor, mycoloyl and quinonyl derivatives of N-acetylmuramyldipeptides were prepared and their immunological properties were investigated. The effectiveness of synthetic adjuvants on the stimulation of nonspecific host resistance against bacterial and viral infections was also discussed.